Pneumatic tool.



No. {i4-9,754. Patented May l5, |900.' C. B. RICHARDS. PNEuMATlc TooL.

(Appmamn mea may 17, 1899.; (No Model.)

2 Sheets-Sheet I.

No. 649,754. Patented May l5, |900.

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` (No Model.) 2 Sheets-Sheet 2.

lUNrrEn STATES# wtrios.

PATENr CHARLES n. RICHARDS, OE CLEVELAND, 'oi-Ho, ssIeNon rro THE CLEVE- LAND PNEUMATIC TOOL COMPANY, OE SAME PLACE.

Pasen/:Arlo TOOL.

SPCFICATION forming part of Letters Patent No. 649,754, dated May 15, 1900. Application filed May 17,1899. Serial No. 717,238. (No model To all whom, it may concern:

Be it known that IJ CHARLES B. RICnAnDs, a citizen of the United States, and a resident of Cleveland, county of Cuyahoga, and State of Ohio, have invented certain new and useful Improvements in Pneumatic Tools, of which the following is a specification, the principle of the invention being herein explained and the best mode in which I have contemplated applying that principle so as to distinguish it from other inventions.

The annexed drawings and the following description set forth in detail one mechanical form embodying the invention, such detail construction being but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings, Figure I represents an axial section of my improved pneumatic tool; Fig. II, an axial section taken in a plane at right angles to said former section, and Figs. III, IV, V, VI, and VII, transverse sections on the lines III III, IV IV, V V, VI VI, and VII VII on Fig. l.

The tool has abarrel portion l and a breechpiece 2, formed with a handle 3, preferably of pistol-grip shape. The barrel is formed with an axial bore 4, in the outer end of which a socket 5, in which the tool is inserted, is secured, and with an axial bore 6 of greater diameter than the former bore. A breechplug 7 is screwed into the rear of said larger bore, in a female-threaded recess in the same, and has a tapering forward end 8 in the form of a rounded cone projecting into said bore. The hammer 9 has a large plunger lO, which iits in the large bore and serves as an actuating-piston, and a smaller head 1l, which fits and reciprocates in the smaller bore and acts against the end of the tool inserted in the socket. The breech-plug has a circular recess 12 in its rear face, into which a valve-casing 13 is secured. Said casing has a diametrical cylindrical distributing-valve chamber la, in which a three-piston distributing-valve l5 slides. Said valve has a middle piston and two end pistons. The rear face of the valvecasing has two inlet-ports 16 and 17, which enter the valve-chamber and may be alternately uncovered by the end pistons of the valve at the extremes of the stroke of the latports 2O and 2l extend from near the ends of the valve-chamber and out through the Walls of the barrel. Exhaust-channels 22 and 23 extend, respectively, from near the rear end of the piston-cylinder slightly in advance of the end of the conical plug and from near the front end of the piston-cylinder slightly to the rear of the port of the channel 19 to near the ends of the valve-chamber, so that their ports in said chamber may be covered or uncovered by the end pistons of the valve at the same time as the exhaust-ports. Ports 24E and 25 are respectively formed in the' ends of the4 valve-chamber and communicate with channels 26 and 27 in the sides of the barrel, which extend, respectively, to about the middle of the piston-cylinder and to a point a short distance forward of the middle of said cylinder. The breech-piece is screwed into the rear end of the barrel and has a chamber 28, which communicates with the inlet-ports of the distributing-valve chamber. An inlet 29 is provided in the breechpiece, to which the supply-pipe for the actuating luid may be connected, and said inlet communicates with an annular inlet-port 30, formed around a controlling-valve chamber 3l in the breech-piece. An annular port 32 is formed around said chamber a short distance above said former port and communicates by a channel 33 with the distributingchamber 28 and with the inlet-ports of the distributing-valve chamber. A two-piston controlling-valve 34 slides in the controllingvalve chamber and has its pistons so spaced that they may connect the two ports in said chamber when the valve is moved downward against the pressure of a spring 35 in the bottom of the valve-chamber, which spring normally forces the valve to close the inlet-port with its lower piston. A screw-threaded stem 36 has its inner end bearing against the upper end of the valve. A collar 37 is firmly secured upon said stein and is engaged by IOC) sleeve slides within the thimble and the screwthread of the stem turnsin the interior screwthread in said sleeve, so that the sleeve may be adjusted in its relation to the stem and the bottom of the thimble by turning the stem. The length of the downstroke of the stem and valve may be adjusted by moving the stop-sleeve to causel it to strike the bottom of the thimble sooner or later in the downstroke of the stem, whereby the opening stroke of the valve is controlled and less or more of the inlet-port exposed. An oilhole 43 is formed in the breech-piece to enter the controlling valve chamber at a point where it will be uncovered when the controlling-valve is in its uppermost or closing position, while it will be covered by the upper piston immediately upon the depression or opening of the valve.

In practice the inlet in the breech-piece is connected by a flexible pipe to a receiver or generator of iiuid under pressure, such as compressed air, gas, or steam. The present hammer is principally intended for use with compressed air as a motive fluid. When no tool is inserted in the socket, the hammerhead may slide out to the end of the socket, whereby the feed-port in the outer end of the piston-cylinder will be covered by the piston and the piston cannot be brought back to start its operation even though the controlling-valve should by accident or otherwise be opened. When the tool is inserted, said inlet-port will be uncovered as the hammer and piston are pushed back, and operation of the hammer will be started by admission of the actuating iiuid through the controllingvalve. If the parts are supposed to bein the position illustrated in the drawings and the controlling-valve is opened by drawing inward upon the finger-lever, and thus pushing the valve down, the fluid enters the upper inlet-port in the distributing-valve chamber and passes through the same and the upper feed-passage tothe rear-of the piston, forcing the same forward and causing the hammerhead to strike the tool. As soon as the piston is forced far enough forward to uncover the port of the passage leading to the upper end of the valve-chamber the iiuid will pass through said passage and force the valve down, thereby opening the rear exhaust and connecting the forward inlet-duct to the inletport in the valve-chamber. This will cause the piston to travel backward until it uncovers the port of the passage leading to the lower end of the distributing-valve chamber, when the valve will again be shifted and the piston driven forward. The piston will be cushioned on its back stroke by shutting oil the exhaust-port before arriving at the end of the stroke, thereby confining a cushion of the actuating iiuid around the conical portion of the breech-plug, which portion will thus form a deep but narrow space of confined iiuid, which will make an eiiicient cushion, diffusing the force of the back jar-to the sides of the barrel. The rear face of the piston is preferably hollowed, so as to admit of its partly fitting over the cone at the eX- tremity ofthe back stroke, thus still more confining the cushion. By pouring oil or other lubricant into the controlling-valve chamber and then opening said valve the oilhole is closed and the oil in the chamber will be carried by the actuating fluid into the distributing-valve chamber and thence into the piston-chamber, thus lubricating all parts of the tool. The breech-plug and the valvecasing are easily accessible by removing the breechpiece, and said parts are securely held in place and protected by said piece.

Other modes of applying the principle of my invention may be employed for the mode herein explained. Change may therefore be made as regards the mechanism thus Vdisclosed, provided the principles of construction set forth, respectively, in the following claims are employed. I therefore particularly point out and distinctly claim as my invention- 1. In a tool operated by huid-pressure, the combination of a piston-cylinder provided with a tapering projection at one end and an exhaust-channel communicating with the interior of said cylinder at a point a distance in-advance of the end of the projection, and f a piston reciprocating in the cylinder,whereby the exhaust-channel is closed by the piston at the rear portion of the back stroke of the same and said stroke of the piston is cushioned by the iuid confined in the narrowing space formed by the tapering projection, substantially as set forth.

2. In a tool operated by Huid-pressure, the combination of a barrel, a piston reciprocating in said barrel, a breech-plug screwed into the breech end of said barrel and formed with a recess in its rear face, a valve-casing secured in said recess and containing the distributing-valve mechanism, and a breechpiece screwed into the breech of the barrel to coniine the breech-plug and the valve-casing in the same, substantially as set forth.

3. In a tool operated by fluid-pressure, the combination of abarrel, a piston reciprocating in said barrel, a breech-plug screwed into f cess in its rear face, a valve-casing secured in said recess and containing the distributingvalve mechanism, and abreech-piece screwed into the breech of the barrel to confine the breeehplug and the valve-casing therein, substantially as set forth.

LI. In a tool operated by fluid-pressure, the combination of a Controlling-Valve chamber, a controlling-valve sliding therein, a spring bearing against one end of said valve, a screwthreaded stem at the other end of the valve, a stopsleeve having said stem threaded through it, and a thimbie in which said sleeve is guided to slide and to be held from turning and against the bottom of which the sleeve may strike, substantially as'set forth.

5. In a tool operated by duid-pressure, the combination of a controlling-valve chamber,

a controllingwaive sliding therein, a spring bearing against one end of said valve, a screwthreaded stem at the other end of the valve, a collar upon said stem, anger-iever engaging said collar, a stop sleeve having said stem threaded through it, and a thimble in which said sleeve is guided to slide and to be held from turning and against the bottom of which the sleeve may strike, substantially as set forth.

In testimony that I claim the foregoing to be my invention I have hereunto set my hand this 1st day of May, A. D. 1899.

CHARLES B. RICHARDS.

Witnesses:

WM. SECHER, K. F. WINDING. 

